US2008316911A1PendingUtilityA1
Simultaneous Cell Group and Cyclic Prefix Detection Method, Apparatus and System
Est. expiryJun 21, 2027(~0.9 yrs left)· nominal 20-yr term from priority
H04L 25/03159H04J 11/0076H04L 27/2666H04L 27/2655H04L 25/022H04L 5/0007H04L 27/2656
52
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Claims
Abstract
A method, and associated apparatus and system, for simultaneous cell group and cyclic prefix (CP) detection, having the steps of determining primary synchronization signal (P-SyS) timing τ using the P-SyS; based on τ, determine a secondary synchronization signal (S-SyS) timing; placing a single Fast Fourier Transform (FFT) window; FFT processing the signal to obtain the frequency domain S-SyS symbols; equalizing the frequency domain S-SyS signal; phase correcting the S-SyS signal; and detecting the cell group and CP length by the correlation giving maximum energy.
Claims
exact text as granted — not AI-modified1 . A method for simultaneous cell group and cyclic prefix (CP) detection, comprising the step of placing a single Fast Fourier Transform (FFT) window for a secondary synchronization signal (S-SyS) between the estimated timing corresponding to an Orthogonal Frequency Division Multiplex (OFDM) symbol transmitted using a long CP or a short CP.
2 . A method for simultaneous cell group and cyclic prefix (CP) detection comprising the steps of:
placing a single Fast Fourier Transform (FFT) window for a secondary synchronization signal (S-SyS) between the estimated timing for a long CP and a short CP; performing a first phase shift of the channel in the frequency domain for the long CP length; performing a second phase shift of the channel in the frequency domain for the short CP relative the channel determined by a primary synchronization signal (P-SyS); phase correcting the received frequency domain transformed S-SyS signal prior to the correlation to the S-SyS sequences; correlating the S-SyS sequences to both corrected signals; detecting the S-SyS sequence and correction providing maximum energy as the cell group and the length of CP.
3 . The method of claim 2 , wherein the timing position is in the middle between the long CP and short CP.
4 . The method of claim 2 , wherein the first phase shift is a positive phase shift and the second phase shift is a negative phase shift.
5 . The method of claim 2 , for use in a user equipment (UE).
6 . A method for detecting simultaneous cell group and cyclic prefix (CP), comprising the steps of:
determining primary synchronization signal (P-SyS) timing τ using the P-SyS; based on τ, determine a secondary synchronization signal (S-SyS) timing; positioning a single Fast Fourier Transform (FFT) window; FFT processing the signal to obtain the frequency domain S-SyS symbols; equalizing the frequency domain S-SyS signal; phase correcting the signal; and detecting the cell group and CP length by the correlation giving maximum energy.
7 . The method of claim 6 , wherein the equalizing step is in accordance with:
Y
_
k
S
-
Sys
=
Y
k
S
-
SyS
H
^
k
≈
±
j2π
·
n
·
k
/
NFFT
S
k
+
e
k
8 . The method of claim 6 , wherein the phase correcting step is in accordance with the formulas:
{tilde over (Y)} k long CP =e −j2π·n·k/NFFT {tilde over (Y)} k S-SyS {tilde over (Y)} k short CP =e j2π·n·k/NFFT {tilde over (Y)} k S-SyS
9 . The method of claim 6 , wherein the correlation providing maximum energy is based on the following formula:
cell
group
,
CP
length
=
arg
(
long
/
short
)
,
m
max
∑
k
=
1
N
used
(
s
k
m
)
·
[
Y
~
k
longCP
,
Y
~
k
short
CP
]
2
m
=
1
…
M
10 . The method of claim 6 , for use in a user equipment (UE).
11 . A method for simultaneous cell group and cyclic prefix (CP) detection, comprising the steps of:
determining a primary synchronization signal (P-SyS) timing; based on the timing, determining secondary synchronization signal (S-SyS) timing; placing a single Fast Fourier Transform (FFT) window; performing a FFT; obtaining S-SyS symbols; testing the S-SyS sequences to phase corrected S-SyS symbols; and obtaining the cell group and CP length based on the best S-SyS correlation match.
12 . The method of claim 11 , wherein the best S-SyS correlation is based on the correlation providing maximum energy according to the following formula:
cell
group
,
CP
length
=
arg
(
long
/
short
)
,
m
max
∑
k
=
1
N
used
(
s
k
m
)
·
[
Y
~
k
longCP
,
Y
~
k
short
CP
]
2
m
=
1
…
M
13 . The method of claim 6 , for use in a user equipment (UE).
14 . An apparatus for simultaneous cell group and cyclic prefix (CP) detection, comprising:
cell search means for determining primary synchronization signal (P-SyS) timing; cell search means for determining secondary synchronization signal (S-SyS) timing based on the P-SyS timing; means for placing a single Fast Fourier Transform (FFT) window; means for performing a FFT; means for obtaining a plurality of S-SyS symbols; means for testing the S-SyS sequences to phase corrected S-SyS symbols; and means for obtaining the cell group and CP length based on the best S-SyS correlation match.
15 . The apparatus of claim 14 , in combination with a UE.
16 . The apparatus of claim 11 , wherein the UE comprises:
an antenna; a front end receiver (Fe RX) having an input coupled to the antenna; an analog to digital converter (ADC) having an input coupled to the output of the Fe RX; a P-SyS correlation module having an input coupled to the output of the ADC; a S-SyS timing module having an input coupled to the output of the P-SyS correlation module; a Fast Fourier Transform (FFT) module having an input coupled to the output of the ADC and an input coupled to the output of the P-SyS module and S-SyS timing module: a phase correction module having an input coupled to the output of the P-SyS correlation module; a channel estimation module having an input coupled to the output of the FFT; a detector module having an input coupled to the output of the FFT and the output of channel estimation module; a S-SyS detector having an input coupled to the output of the phase correction module and the output of the channel estimation module, wherein the P-SyS timing τ and S-SyS timing are determined using the P-SyS, at P-SYS correlation module, the FFT window is placed and the signal is FFT processed to obtain the frequency domain S-SyS symbols at FFT module and the cell group and CP length detected at S-SyS detector are given by the correlation giving maximum energy in S-Sys detector module.
17 . The apparatus of claim 16 , for use in an Orthogonal Frequency Division Multiplexing (OFDM) modulation system.
18 . An Orthogonal Frequency Division Multiplexing (OFDM) modulation system, comprising:
a module for determining primary synchronization signal (P-SyS) timing τ using the P-sys; a module for determining a secondary synchronization signal (S-SyS) timing based on τ; a module for placing a Fast Fourier Transform (FFT) window; a FFT module for processing the signal to obtain the frequency domain S-SyS symbols; a module for equalizing the frequency domain S-SyS signal; a module for phase correcting the signal; and a module for detecting the cell group and CP length by the correlation giving maximum energy.
19 . The system of claim 18 , in combination with a user equipment (UE) for use in a Long Term Evolution system.
20 . The OFDM modulation system of claim 18 , wherein the correlation providing maximum energy is based on the following formula:
cell
group
,
CP
length
=
arg
(
long
/
short
)
,
m
max
∑
k
=
1
N
used
(
s
k
m
)
·
[
Y
~
k
longCP
,
Y
~
k
short
CP
]
2
m
=
1
…
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